Not enough ads? Google gives more ads

Can you see what the white arrow pointing to? Yes, that is the weird images or characters or arrows or anything that you want to call it. I was too curious and I hover my cursor on one of the arrows and the colour changed. I assumed it might be another new feature that Google put onto my adsense. Then I clicked it.

Dang! The ad sliding up and display another ads. Owh…it actually will give more ads to your visitors. It gives more choices to them which mean it will give more clicks for you. Remember, more clicks will give you more money. Thanks to Google for adding this feature to our Adsense.

Have you found this thing on your Adsense? Is it new feature from Google or you already know about it before I found this thing?